1st equation should be multiplied with 3 
6x+9y=24
-6x+4y=11
________
13y=35
y=35/13 
2x+3y=8...1
put y=35/13 in 1
2x+3(35/13)=8
26x+105=104
26x=-1
x=-1/26
        
             
        
        
        
The Answer Is 6x
Hope This Helps
        
                    
             
        
        
        
4 1/2(2)=9. Multiply by 2 to get total
9- 3 1/2=z. Subtract 3 1/2 from total to get Z
5 1/2= Z
        
             
        
        
        
You need to divide the minutes by hours 
 
        
                    
             
        
        
        
0.48 miles
Step-by-step explanation:
Step 1
It is given that the grade(slope) is 4%. This means that for every 100 miles traveled, the elevation changes by 4 miles. 
Step 2
Hence for a distance of 12 miles , the elevation changes by 12*4/100 = 48/100 = 0.48 miles. [Using direct proportion]